Do you think these 180 000 people will be able or willing to join a club? With a mandatory membership fee and legally mandated minimum membership period of three months?

As these clubs are not allowed to hire people and are also forbidden to allow non-members to act on club duties, a membership will mean some work too. How many of the 180 000 are willing to put in that effort.

It doesn't matter whether or not they will join a club. It matters that simply owning (a non-negligible amount of) cannabis is no longer illegal.